Timer to something

Timer

function countdown(dateEnd) {
    var timer, days, hours, minutes, seconds;
   
    dateEnd = new Date(dateEnd[0], dateEnd[1] - 1, dateEnd[2], dateEnd[3], dateEnd[4], dateEnd[5]);
    dateEnd = dateEnd.getTime();

    if ( isNaN(dateEnd) ) {
      return;
    }
   
    timer = setInterval(calculate, 1000);
   
    function calculate() {
      var dateStart = new Date();
      var dateStart = new Date(dateStart.getUTCFullYear(),
                               dateStart.getUTCMonth(),
                               dateStart.getUTCDate(),
                               dateStart.getUTCHours(),
                               dateStart.getUTCMinutes(),
                               dateStart.getUTCSeconds());
      var timeRemaining = parseInt((dateEnd - dateStart.getTime()) / 1000);

      if ( timeRemaining >= 0 ) {
        days = parseInt(timeRemaining / 86400);
        timeRemaining = (timeRemaining % 86400);
        hours = parseInt(timeRemaining / 3600);
        timeRemaining = (timeRemaining % 3600);
        minutes = parseInt(timeRemaining / 60);
        timeRemaining = (timeRemaining % 60);
        seconds = parseInt(timeRemaining);

        $('.preview__time-days').html(parseInt(days, 10));
        $('.preview__time-hours').html(('0' + hours).slice(-2));
        $('.preview__time-minutes').html(('0' + minutes).slice(-2));
        $('.preview__time-seconds').html(('0' + seconds).slice(-2));
      } else {
        return;
      }
    }
  }
  
  countdown($('.preview__set-time').html().split(','));
  
  
  	<!-- ЗАДАВАТЬ ТОЧНО В ТАКОМ ФОРМАТЕ! ГОД, МЕСЯЦ(01,02,03), ДЕНЬ, ЧАС, МИНУТА, СЕКУНДА-->
						<div class="preview__set-time visually-hidden">2019, 05, 30, 5, 24, 0</div>
						<div class="preview__time">
							<span class="preview__time-days"></span>
							<span class="preview__time-hours"></span>
							<span class="preview__time-minutes"></span>
							<span class="preview__time-seconds"></span>
						</div>